Please follow the troubleshooting steps below:
1. Test the microphone with the bundled Sound Recorder. If the microphone works well, please check if there is problem with the receiver of the recipient's phone.
2. Enable amplication function during a call on recipient's phone to check if they can hear your voice.
3. Please test whether the phone device is working under different circumstances/situations.
4.Reboot your phone.
5.. Update firmware to latest version：Go to Settings > System > System updates > Check now.
6. Access Safe Mode by long pressing the Power key > Tapping and holding Power Off > Tapping OK. If your phone works well in Safe Mode, there may be some 3rd apps that are causing the malfunction. Please reboot your phone and check again.
7. Backup your data and perform a Factory Data Reset.
If the above steps don't resolve the issue, please contact ASUS Product Support for help.
